Abstract
A new method for the synthesis of 2-substituted 6-methylpurine ribosides from guanosine is described. Reaction of N (2), O (2'), O (3'), O (5')-tetraacetyl-O (6)-p-toluenesulfonylguanosine with carbanion from ethylacetoacetate gave the 6-ethoxycarbonylmethyl derivative, which was further converted to 2-amino-6-methylpurine riboside by deacetylation and decarboxylation. Replacement of the amino group of the compound by the fluoro group was achieved by the Schiemann reaction. The fluoro group could easily be replaced by several nucleophiles. As a result, 2-methylthio-, and 2-dimethylamino-6-methyl-9-β-D-ribofuranosylpurines could be effectively prepared.
